Author Topic: Desalination - Would you drink this water?  (Read 1593 times)

Offline El Sid

Re: Desalination - Would you drink this water?
« Reply #30 on: February 06, 2018, 10:46:41 AM »
I heard that desalination is bad for the sea life though. In a radio interview the "expert" said that the saline water, that is left over once the clean water is removed, is a gel-like substance. It drops to the bottom of the ocean and does not dissolve and mix with the sea water easily again. Because of the high salt content it kills everything it comes in contact with.
Not sure how true this is though.

In a properly designed system the brine outfall will be located where there is sufficient current to disperse it. So in the immediate vicinity of the outfall it is concentrated but is soon diluted (or should be). Also (in the projects I have worked on anyway), seawater RO plants have about a 50% yield, so the brine is only double the concentration of the seawater, not a gel that sinks to the bottom.

Offline vleisman

Re: Desalination - Would you drink this water?
« Reply #31 on: February 06, 2018, 12:19:11 PM »
Stick to Namibian imports so that you help preserve the precious SA water resources. Drink imported, pee localy.

Except for Carvers, the exception that proves the rule  :dop:

Offline Trompie67

Re: Desalination - Would you drink this water?
« Reply #32 on: February 06, 2018, 01:04:17 PM »
Nope, you got pwned, as the youngsters say.

I'm a youngster.
It's not a burn.
*facepalm*

1) slang: to disrespect someone (to diss); to make fun of someone; used by a third party after a first party makes fun of a second party.

 By merely stating he has a phd does not make it a burn.

You learn something every day

OK then, in Old Toppies lingo: You just got your sarcastic attitude b!tchslapped into next week.

Personally I thought "burn" was far more polite, but as you insist.....  :BWAHAHAH:
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Offline fdlsys

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Re: Desalination - Would you drink this water?
« Reply #33 on: February 06, 2018, 01:05:54 PM »
^^^  :point: :ROFLMAO:
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Offline Shonver

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Re: Desalination - Would you drink this water?
« Reply #34 on: February 06, 2018, 01:07:26 PM »
Hey, go easy on the guy. I mean... what were the chances?

 :giggle:
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Offline Gerlach

Re: Desalination - Would you drink this water?
« Reply #35 on: February 06, 2018, 01:24:44 PM »
We're about to start filtering and purifying our wellpoint water which is quite high in calcium/scale. Just waiting for the sample to be returned from testing and then we can go ahead.

Hopefully there is no large amount of iron in the water, that can get quite costly to remove depending on how much manual labour you're prepared to put in.

Juggy, what did the testing cost and where did you send it off to? Did my own Wellpoint 2 weeks ago and got water from 2 to 3 meters. Was actually really easy to do it.
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Online Juggy

Re: Desalination - Would you drink this water?
« Reply #36 on: February 06, 2018, 01:26:53 PM »
Juggy, what did the testing cost and where did you send it off to? Did my own Wellpoint 2 weeks ago and got water from 2 to 3 meters. Was actually really easy to do it.

Haven't received the results yet but my plumber sent it in to a place in Woodstock. Cost R1500 for the test, probably less if I did it myself.

That is quite impressive doing it yourself. I need to get someone out to come and fix mine. After 4-5 hours the water runs back down the pipe and I need to prime it up to 10 times to get it going again.

Apparently the sock is broken whatever that is.

Offline Shonver

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Re: Desalination - Would you drink this water?
« Reply #37 on: February 06, 2018, 01:28:56 PM »


Did my own Wellpoint 2 weeks ago and got water from 2 to 3 meters. Was actually really easy to do it.

How?



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Online JonnyP

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Re: Desalination - Would you drink this water?
« Reply #38 on: February 06, 2018, 01:33:32 PM »
In a properly designed system the brine outfall will be located where there is sufficient current to disperse it. So in the immediate vicinity of the outfall it is concentrated but is soon diluted (or should be). Also (in the projects I have worked on anyway), seawater RO plants have about a 50% yield, so the brine is only double the concentration of the seawater, not a gel that sinks to the bottom.

I think there would be some way to go before the desalination plants had an effect on the sea water.  As El Sid says, they do not super concentrate the saline solution in this case, and the ocean currents should mix and disperse the salt effectively.  Over a prolonged period it shouldn't be to much of an issue if it is just Cape Town.  In areas where there is little mixing and a lot of desalination, there can be an effect over time although this is only being researched to any extent now.  An example being the Gulf states:

https://www.sciencedirect.com/science/article/pii/S0307904X06002241
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Offline Gerlach

Re: Desalination - Would you drink this water?
« Reply #39 on: February 06, 2018, 01:58:49 PM »
Haven't received the results yet but my plumber sent it in to a place in Woodstock. Cost R1500 for the test, probably less if I did it myself.

That is quite impressive doing it yourself. I need to get someone out to come and fix mine. After 4-5 hours the water runs back down the pipe and I need to prime it up to 10 times to get it going again.

Apparently the sock is broken whatever that is.

I was impressive with my self to. I used my father 0.75hp wellpoint/"boorgat" pump, got a 6 meter "cut it down to 4.5meter"  length of the 40mm Blue pvc pipe, got some fittings, 2X220 liters of gray water from his system. Mark the pipe off every half meter with a marker to see how deep i'm going. Then i used some 32mm black Class 9 pvc pipe that i cut some small grooves at one end and sealed the end of. About 3 Bar of pressure and whooppp, down the blue pipe go in to the ground. Then i sleeved the black 32mm pipe down the blue 40mm pipe.

I actually open up the yesterday again. My father got some 60mm galv pipe and made some fittings, so you don't have that flex on the pipe and you can control it better. Pulled the black pipes out to put the Sock over the end to filter the sound out.

The sock that you are talking about is called a  "bwhurm or something like that". It help to filter the water that the pump don't suck sand up and damages the pump propeller. let me know if are looking for some. I bought some from Spilhaus.

To sort out that problem of yours of the water running back, you need a One Way Valve. It will stop the water running back. you need to connect it right at pump input.A Spring loaded Brass one. You can buy them from Andrag and STEWARTS & LLOYDS. STEWARTS & LLOYDS is super cheap.





« Last Edit: February 06, 2018, 02:03:58 PM by Gerlach »
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Online Juggy

Re: Desalination - Would you drink this water?
« Reply #40 on: February 06, 2018, 02:44:27 PM »
I was impressive with my self to. I used my father 0.75hp wellpoint/"boorgat" pump, got a 6 meter "cut it down to 4.5meter"  length of the 40mm Blue pvc pipe, got some fittings, 2X220 liters of gray water from his system. Mark the pipe off every half meter with a marker to see how deep i'm going. Then i used some 32mm black Class 9 pvc pipe that i cut some small grooves at one end and sealed the end of. About 3 Bar of pressure and whooppp, down the blue pipe go in to the ground. Then i sleeved the black 32mm pipe down the blue 40mm pipe.

I actually open up the yesterday again. My father got some 60mm galv pipe and made some fittings, so you don't have that flex on the pipe and you can control it better. Pulled the black pipes out to put the Sock over the end to filter the sound out.

The sock that you are talking about is called a  "bwhurm or something like that". It help to filter the water that the pump don't suck sand up and damages the pump propeller. let me know if are looking for some. I bought some from Spilhaus.

To sort out that problem of yours of the water running back, you need a One Way Valve. It will stop the water running back. you need to connect it right at pump input.A Spring loaded Brass one. You can buy them from Andrag and STEWARTS & LLOYDS. STEWARTS & LLOYDS is super cheap.







Thanks, I have replaced the one way valve already but the problem persists

Nice job on the wellpoint, shows what you can do if you apply yourself.

Offline LouisF

Re: Desalination - Would you drink this water?
« Reply #41 on: February 06, 2018, 02:46:19 PM »
Windhoek has been recycling purified and treated sewage water for ages - has a slight pong from dissolved gasses but you get used to it.. :giggle:
This process was implemented way back in the late '50s/early 60s. I lived on that water fro a number of years. No problem.
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Offline Gerlach

Re: Desalination - Would you drink this water?
« Reply #42 on: February 06, 2018, 02:50:55 PM »
Thanks, I have replaced the one way valve already but the problem persists

Nice job on the wellpoint, shows what you can do if you apply yourself.

Just check all your clamps and stuff. Maybe a spot that's sucking air. I sealed all my joints with sealer before clamping them down.
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Offline mahleu

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Re: Desalination - Would you drink this water?
« Reply #43 on: February 06, 2018, 02:51:40 PM »
There's a guy in Durban with a system that turns humidity into water, he has a big version mounted on a small truck.
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Online JonnyP

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Re: Desalination - Would you drink this water?
« Reply #44 on: February 06, 2018, 04:06:38 PM »
There's a guy in Durban with a system that turns humidity into water, he has a big version mounted on a small truck.

You can buy systems to do that but the power they use makes it not really worthwhile unless you have a water crisis like this one!  Alternately, stand your ice cold beer in a pot for a minute or so at first and between sips.  By the end of the braai you should have enough water to wash your hands.
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